When one tester packed the Copper Spur for a weekend trip in Colorado’s Indian Peaks with his wife, three kids, and dog, the missus looked at the little bundle strapped to his pack and asked, dismayed, “Are you bringing two of those?”

But she became a believer when he pitched the shelter (with the help of a nine-year-old, it took just a few minutes), and the family of five plus pooch crawled in. Wall-to-wall headroom with a peak height of 50 inches—and a generous 57-square-foot floor—make the Copper Spur so spacious that, in Capitol Reef National Park, eight (adult) testers squeezed in for dinner and a card game during a snowstorm. The crew cooked in one 13.5-square-foot vestibule and stored a couple of packs in the other.

The key to the amazing space-to-weight ratio? Ultralight fabrics like 15-denier siliconized nylon in the fly (which contribute to the high price), and the same stable, efficient, hubbed pole system that earned the Copper Spur UL3 a 2008 Editors’ Choice Award. Like the smaller version, this one proved dry and stable in typical three-season storms. And ventilation, thanks to high vents and plenty of mesh, is superb; with temps in the low 30s, even our family of five saw no condensation inside the canopy (though there was moisture on the fly’s interior).

The wispy materials held up well to kid and canyon abuse, and while the fly fabric is prone to catching in the zipper, it never ripped. Downside? “With this much space,” says our tester, “I don’t have an excuse for making the dog sleep in the vestibule.” $600; 5 lbs. 10 oz. (fly, canopy, poles); bigagnes.com